E: cat4@york.ac.uk

Nurses, decisions and irreducible uncertainty in practice

Carl Thompson PhD, RNSenior Lecturer, Health Sciences Editor: Evidence Based Nursing

www.ebn.bmj.com

Good idea bad idea?

Exercise program for hospital nurses

Bicycle education

Lying babies prone for sleep

On “irreducible” uncertainty

“It is impossible to calculate accurately events that are determined by chance”…

But let us not be afraid of this fact…

Thucydides: History of the Peloponnesian war.

“seeing” in healthcareSlide from Slawson, Shaughnessy, Becker, 1999.

Lets agree to disagree

uncertainty reduction via synthesis

Half-empty or half-full?

Finite uncertainty in nursing

• Intervening– Prevention– Timing – Targeting– referal

• Communicating• Service delivery & organisation• Diagnosis• Information seeking• Experiential, understanding or hermeneutic

Thompson et al. 2001-2005Journal of Advanced Nursing

Erm...yes, about that…

There is a problem with intuition

“Whenever there is a simple error that most layman fall for there is always a slightly more sophisticated version of the same problem that experts fall for” (Amos Tversky, NY Times, 6-12-1983)

“comfortable” doesn’t make it right

“in all life one should comfort the afflicted, but verily, also, one should afflict the comfortable, and especially when they are comfortably, contentedly, even happily, wrong.” (JK Galbraith, The Guardian, 28-7-1989)

So… what of this mythical 6th sense

• are nurses as good at identifying “signals” in “noisy” clinical settings as we think?

• do we recognise our limitations and adjust our confidence accordingly?

• If not why not?

Signals and noise: risk assessment

  risk No risk

Yes TP FP

no FN TN

Signals and noise: risk assessment

Thompson C, Dalgleish L et al. The effects of time pressure and experience on nurses' risk assessment decisions: a signal detection analysis. Nursing Research, 2008; 57(12): 302-311

Signals and “real life” pressures

100% more likely to intervene

23% vs. 27% less “misses”

but

Time pressure = no benefit

Thompson C, 2008 et al.

“I intuit therefore I am”

Student vs. Nurse

0.500

0.600

0.700

0.800

0.900

1.000

50 60 70 80 90 100

Confidence Response

Pro

po

rtio

n C

orr

ec

t

student

nurse

reference line

Huiqin Yang 2008

“singing while you’re winning”

Easy Cases: No time Pressure vs. Time Pressure

0.5

0.6

0.7

0.8

0.9

1

50 60 70 80 90 100

Confidence Response

Prop

ortio

n C

orre

ct

no time pressure

time pressure

reference line

Huiqin Yang 2008

“when the going gets tough the tough start guessing”

Difficult Cases: No Time Pressure vs. Time Pressure

00.10.20.30.40.50.60.70.80.9

1

50 60 70 80 90 100

Confidence Response

Pro

po

rtio

n C

orr

ec

t

no time pressure

time pressure

reference line

Huiqin Yang 2008

Understanding through decomposition

Dx “at risk” 3 – 50 out of 50 Rx “intervene” 4 to 48 out of 50

Decomposing judgements

0-.2 nada

.2 - .4 Low

.4 - .6 Middling

.6 - .8 Marked

>.8 high

Achievement .42

consistency .79

Linear reasoning

.50

R2 96%

Non-linear reasoning

.06

“Jerry” moment

"Restlessness and discontent are the first necessities of progress."

Thomas Eddison